Field compilation map of the geology of the Keystone area, Black Hills, South Dakota

Locatable Mineral Reports for Colorado, South Dakota, and Wyoming provided to the USDA Forest Service in Fiscal Years 2006-2009

“…The Norbeck parcel is underlain by Proterozoic quartz mica schist, quartz schist, and quartzmica-staurolite schist (map unit qm of Norton, 1976;Attachment D). There may be a very thin band of graphite schist in the southwestern corner of the tract.…”

Locatable mineral reports for Colorado, South Dakota, and Wyoming provided to the U.S. Forest Service in fiscal year 1998

“…A Geologic map of part of Mount Rushmore quadrangle (Norton, 1976 Fig. 3 Miscellaneous area parcels HES 345 Custer quadrangle Fig.…”

“…There are several other mines and prospects in the vicinity, none with recorded production. Pearson (1980) assumed the ore came from a small pocket and presented no evidence that larger deposits This tract is in quartz schist, quartz-mica schist, and quartz-mica-staurolite schist (Norton, 1976; see attachment A) that corresponds with Early Proterozoic graywacke (DeWitt and others, 1989).…”

“…On a site-specific scale, and based on lack of prospects and pegmatites at 1:24,000 scale geologic mapping (Norton, 1976), the potential is low to moderate.…”

Structural geology and tectonics of the paleoproterozoic rocks of the Mount Rushmore Quadangle, Black Hills, Souh Dakota

“…During World War II and after, the Black Hills were a locus of numerous investigations by the United States Geologic Survey (e.g., Fisher, 1942Fisher, , 1945Gwynne, 1944;Noble and Harder, 1948;Noble et al, 1949;Sheridan et al, 1957;Norton et al, 1962). Previous mapping of the study area was conducted by Norton (1976). Mapping adjacent to and within close proximity of the study area was conducted by Redden (1963Redden ( , 1968, Ratte and Wayland (1969), Bayley (1970, 1972a, 1972b, Woodland (1979).…”